Heretofore, wreckers have for the most part been marketed as special purpose trucks, or have required dealer fabrication or assembly of wrecker apparatus on existing heavy duty trucks. Each of these types of wreckers is rather expensive and as a result, small service stations and garages having light duty and relatively infrequent towing requirements find it difficult to justify the purchase of such wreckers.
With a view towards providing a wrecker of light duty towing capacity at a price affordable by small service stations and garages, it has been proposed to provide various types of wrecker attachments adapted to be mounted on pickup trucks for the purpose of converting same into light duty wreckers. One such wrecker attachment is disclosed in U.S. Pat. No. 3,888,368, wherein it is proposed to provide a base supporting member fabricated from a plurality of telescopically associated members fitted with holes adapted to receive for attachment mounting purposes bolts commonly used for securing the bed of a pickup truck to its frame. This construction has the advantage of permitting the wrecker attachment to be directly fixed to the frames of trucks of differing construction. However, drawbacks of this prior wrecker attachment would appear to be the complexity and resultant cost of fabricating its base support member, and the liklihood that the frictional coupling provided between its telescopically associated members will eventually allow undesired relative movement of such members with resultant displacements of the wrecker attachment relative to the truck bed during use. Also, the bolts typically employed for mounting a bed on the frame of a pickup truck are not designed to withstand the shear and/or tension loadings expected to be imposed thereon, during use of such truck as a wrecker.
A light duty wrecker attachment for pickup trucks has also been disclosed in U.S. Pat. No. 4,269,396. This wrecker attachment has the advantage over that described in the above patent of permitting mounting/dismounting thereof relative to a truck, without requiring disassembly of its bed relative to its frame. However, this latter wrecker attachment is believed to have the decided disadvantage of not being firmly secured to the truck frame during use.